5.9 Manifold & Throttle Body for 3.9

asilaydying · #1 07-01-2008, 07:43 PM

I want to do a manifold/throttle body swap for my 3.9. I found a stock manifold and throttle body from a 5.9. (cheaper than buying a billet or summit)
From what I've read so far I'll just need a throttle cable and gaskets to pull this off. (I am a beginner level mechanic)
I'll get 5 to 8 more horsepower mostly in the higher rpm range.
Two questions, am I missing anything? and is an original 5.9 manifold worth the upgrade?

spencea15 · #2 07-01-2008, 07:54 PM

Ok yes you can put a 5.9l throtle body on you engine to gain some upper power.

You can not change the intake manifold between the two motors one is for a V6 and the other for a V8.

You will have to get a new throtle cable.

wink2873 · #3 07-01-2008, 07:57 PM

lol, if you can find a way to bolt up a v8 intake manifold to a v6 let me know.

mikec04 · #4 07-01-2008, 09:12 PM

Might be able to do it, but you will have one helluva vacuum leak

asilaydying · #5 07-01-2008, 09:54 PM

[sm=smiley9.gif] I did not think that one all the way through. There is a throttle body attached to a manifold for sale that i want to pick up, which led to the question. thanks(shrinks away)

01SilverCC · #6 07-01-2008, 11:31 PM

For me the V8 TB addedsome gain at highway speeds and when passing. My 3.9 seems to pull a little harder from a dead stop withthe V8 TB on it. Istill cruise around 75 mph on theinterstatebut I spend less timegetting to 75-80 mph.It also seems to have given me a little more MPG.

Take my advice(I did it the hard way the first time) and getthe TB cable from the donor truck too. It will interchange with your truck easily. Trying to modify the V8 TB linkage was a royal pain and it did not work well for me at all. Get a new TB gasket and swap over your originalTPS,IAC and MAP sensorsto the new TB since you know they work OK. Clean the newTB well before installing it and enjoy.

Jimmy

wink2873 · #7 07-02-2008, 07:38 AM

ask them if they will just sell the TB. i paid 50 bucks for mine, plus 30 for a new throttle cable. i ordered it from www.dodgeparts.com . it did add a nice gain in power, but i have a stage one intake manifold from hughes engines so i cant say what it will do on a stock manifold.

RoaminGnome · #8 07-03-2008, 10:41 PM

Will a V8 TB give any gains at lower RPMs? Like under 2500? I wanna do this but if I tow or haul I dont wanna lose any of my low end. Its a 3.9 it doesnt have much to start with[:'(]

01SilverCC · #9 07-03-2008, 10:59 PM

On mine it didn't really affect the low end. I don't tow anything so I don't know how it might affect towing.Torque feels the same, it does pull away from a stop faster, like from when you get going after a stop sighn or red light. Italsofeels like itpulls somewhatharder at lowerRPM than with the v6 TB. The mainimprovements I noticed were at highway speeds from like 1500 RPM and up,like 45 or 50 mphon up to 75 or so. I spend less time getting to cruising speed. And I can pass other cars and get up on the interstate easier. If I am cruising along and need to pass it has a noticeable gain in power than with the old TB. It's not like driving a V8, but it did make a noticeableimprovement tothe performance. I get a little better MPG with it too, not much maybe 2 to 3 moreMPG. Nowadays every little bit helps a lot on that.

Jimmy

asilaydying · #10 07-04-2008, 03:57 PM

What is the part number for the stage one intake?